Cardiovascular disease (CVD) is the general term for heart and blood vessel diseases, including atherosclerosis, coronary heart disease, cerebrovascular disease, aorto-iliac disease, and peripheral vascular disease. Subjects with CVD may develop a number of complications, including, but not limited to, myocardial infarction, stroke, angina pectoris, transient ischemic attacks, congestive heart failure, aortic aneurysm and death. CVD accounts for one in every two deaths in the United States and is the number one killer disease. Thus, prevention of cardiovascular disease is an area of major public health importance.
A low-fat diet and exercise are recommended to prevent CVD. In addition, a number of therapeutic agents may be prescribed by medical professionals to those individuals who are known to be at risk having CVD. These include lipid-lowering agents that reduce blood levels of cholesterol and trigylcerides, agents that normalize blood pressure, agents, such as aspirin, or platelet ADP receptor antagonists that prevent activation of platelets and decrease vascular inflammation (e.g., clopidogrel and ticlopidine), and pleiotrophic agents such as peroxisome proliferator activated receptor (PPAR) agonists, with broad-ranging metabolic effects that reduce inflammation, promote insulin sensitization, improve vascular function, and correct lipid abnormalities. More aggressive therapy, such as administration of multiple medications or surgical intervention may be used in those individuals who are at high risk of having CVD. Since CVD therapies may have adverse side effects, it is desirable to have methods for identifying those individuals who are at risk, particularly those individuals who are at high risk of experiencing an adverse cardiac event near term.
Major risk factors for cardiovascular disease include age, hypertension, family history of premature CVD, smoking, high total cholesterol, low HDL cholesterol, obesity and diabetes. The major risk factors for CVD are additive, and are typically used together by physicians in a risk prediction algorithm to target those individuals who are most likely to benefit from treatment for CVD. Testable markers of CVD include: level of aortic plaque formation, total blood cholesterol level, blood triglyceride level, blood low density lipoprotein levels, blood high density lipoprotein levels, formation of foam cells, and levels of choline-related trimethylamine (TMA) and trimethylamine-containing compounds, such as trimethylamine N-oxide (TMAO).